"Monster" Lake's Rare Giants Lure Anglers, Biologists

Standing on the shores of Thailand's Lake Monster, angler Brendan O'Sullivan knew there were endangered giants lurking near his baited hook—and that conservationists were happy to have him score a rare catch.

The 7-acre (2.8-hectare) lake is one of several created in recent years near Bangkok for anglers who want to hook some of the world's most exotic fish.

Lake Monster alone boasts roughly two dozen types of freshwater fish, many of them threatened with extinction.

While this might seem like a conservationist's nightmare, some praise the operation as an example of a burgeoning partnership between anglers and biologists who hope that catch-and-release sportfishing could help save at-risk animals.

"This is allowing anglers to catch rare species without having to go into the wild and try to remove a very rare fish from its natural habitat," said Zeb Hogan, a fisheries biologist at the University of Reno in Nevada.

As head of the National Geographic Society's Megafishes Project, Hogan is leading efforts to find, study, and preserve the world's largest freshwater fish, some of which are highly endangered but poorly understood, compared to ocean going behemoths. (National Geographic News is part of the National Geographic Society.)

Part of the project is to analyze catch records to learn more about population trends. The data provide valuable information on the animals' abundance, size, and movements, Hogan said.

"It's become more common for me to team up with recreational fishers who share the same goal. That is, to catch these fish but also to release them," he added. "What we should do is minimize the harm to the fish and maximize the information we're gaining in order to protect them."

Evolving Partnership

In some cases, artificial lakes and breeding centers can be the only places where experts can study rare species in the flesh.